EP 0174721 A2 19860319 - Apparatus for processing image signal.
Title (en)
Apparatus for processing image signal.
Title (de)
Bildsignalverarbeitungsgerät.
Title (fr)
Appareil pour le traitement d'un signal d'image.
Publication
Application
Priority
- JP 15438784 A 19840725
- JP 15438984 A 19840725
- JP 15439084 A 19840725
- JP 15439184 A 19840725
- JP 15439784 A 19840725
- JP 15439884 A 19840725
- JP 17065784 A 19840816
Abstract (en)
The invention relates to a method for processing an image signal such that areas of original image data are sequentially scanned with a scanning window having a size corresponding to M picture elements in units of a predetermined number of picture elements so as to perform halftone display in accordance with black-and-white binary distribution with respect to the signal levels of the picture elements within the scanning window every time the scanning window is moved. The picture elements within the scanning window are assigned an order of preference in accordance with their image signal levels. A sum of the image signal levels of the picture elements within the scanning window is calculated, and A and N of the equations S = C x N + A are calculated, where C is a predetermined image signal level (e.g., black level and maximum level), N is an integer, and A is the image signal level falling within the range O </= A < C As a result of the preference operation, N picture elements are assigned a level C, the next picture element is assigned a level A, and the remaining picture elements, O. In order to impart regularity to the converted image signal distribution, additional data is added to the preference data.
IPC 1-7
IPC 8 full level
H04N 1/405 (2006.01)
CPC (source: EP US)
H04N 1/4052 (2013.01 - EP US)
Citation (applicant)
- US 5021873 A 19910604 - ABUMI TAKAO [JP]
- GB 2129652 A 19840516 - MATSUSHITA ELECTRIC IND CO LTD
Designated contracting state (EPC)
DE GB
DOCDB simple family (publication)
EP 0174721 A2 19860319; EP 0174721 A3 19870826; EP 0174721 B1 19910717; DE 3583474 D1 19910822; US 4692811 A 19870908
DOCDB simple family (application)
EP 85305304 A 19850725; DE 3583474 T 19850725; US 75896185 A 19850725